In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x +

Question

In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 10)°, find the number of degrees in angle B.

(A) 20
(B) 40
(C) 50
(D) 60
(E) 80

Loop123 · Answer

If they are isosceles(AB=BC) then (4x – 30)°=(2x + 10)°

x=20

2(20)+10= 50 
180- 50(2)=80

E

stne · Answer

Bunuel ,

Equal to sign in misplaced, making it hard to understand the question. Hope you will look into this. Thank you.

Bunuel · Answer

___________________
Edited. Thank you!

imeanup · Answer

In  	riangle ABC, AB=BC, i.e. \angle A=\angle C 
 4x-30^{\circ}=2x+10^{\circ} 
 x=20^{\circ} 
Now, substitute the value of  x  in any of the above equations, i.e.  \angle A=\angle C = 50^{\circ} 
 \angle B = 180^{\circ} - (50^{\circ}+50^{\circ}) = 180^{\circ}-100^{\circ} =80^{\circ} 
 Ans E

CrackverbalGMAT · Answer

SOLUTION:

Since AB=BC, 
4x−30=2x+10
=>x=20∘
Thus 4x-30=50 and the other angle 2x+10 should also be 50.
The third angle asked =180-(50+50)=80    (OPTION E)

Miss Devmitra Sen (Math)

MHIKER · Answer

That means Angle A=Angle C

or,  4x-30=2x+10

2x=40

x=20

A=C=2x+10=40+10=50, \ Thus \ B=80

In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x +

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GMAT Problem Solving (PS) Questions

In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x +

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